The paired eversible vesicles on the postabdomen of male T. notata are likely to play an important role in intraspecific communication and possibly in the notorious aggregation behaviour of these flies at buildings in autumn. The morphological and histological study of these organs provides new evidence supporting the hypothesis that they are pheromone glands. They also constitute a strong optical signal. A detailed survey of these structures could provide the bases for targeted control methods.
Subepidermal glands of the body of Troglocaridicola sp. (from the cavemicolous shrimp Troglocaris sp. in eastern Italy) were observed by transmission electron microscopy. The reservoir and duct of the glands arc lined with longitudinal microlubulcs. Membrane-bound granules inside the gland show a distinctive pattern: they contain fibres, 18 nm in diameter, regularly arranged in bundles with a 5 nm space between libres. From a survey of the available literature on glands of Platyhelminthes, it is concluded that this structure is known only in this species. Glands with regularly arranged 18 nm fibres, if characteristic for the Scutariellidae, could be considered an autapomorphy of this family, distinguishing it from other members of the Temnocephalida.